How Letting Kids Get Dirty Helps Protect From An ‘Oversanitized World’

We all want what is best for our kids. The problem is that there is no perfect handbook on how to raise them, nor is there any one best way, either. We read books and articles, talk to friends, and try to remember (or forget!) how our parents raised us. Both of us have children and have struggled and muddled through the parenting process the same way everyone does. We are also scientists who have worked with microbes for many years, and we couldn’t help but consider how these ever-present microbes influence development as we raised our children. At first we studied microbes that cause disease, and we feared them just like anyone else. But more recently we began taking notice of all other the microbes that live in and on us — our “microbiota.” As we continue to study the microbiota of humans, it is becoming clear that our exposure to microbes is most important when we’re kids. At the same time, modern lifestyles have made childhood much cleaner than ever before in human history, and this is taking a huge toll on our microbiota — and our lifelong health.

The genesis of this book came from the realization that the studies in our lab — and the labs of several other researchers — prove that microbes really do impact a child’s health. What shocked us most was how early this starts — the first one hundred days of life are critical. We knew microbes played a role in well-being, but we had no idea how soon this role began.

Several other factors converged to help convince us to write this book. Claire has young children, and all of her young parent friends were extremely interested in the concept of microbes and how they might affect their kids. Whenever we tell other parents about our work, the questions never cease — Do I need to sterilize their bottles every time? What kind of soap should I use? We realized that there are many questions out there about microbes . . . and a lot of wrong information.